Power plant



L. LUSTIG POWER PLANT Feb. 22, 1938.-

Filed June 25, 1934 2 Sheets-Sheet 1 4 8 EXH/Yl/JTEI? P947 Mot El?DEM/51V Pun 7P INVENTOR [HOW/6 1057/3. 4o 4! BY 4 RNEY ATTO

L. LUSTIG POWER PLANT Feb. 22, 1938.

Filed June 25, 1934 2 Sheets-Sheet 2 94 f? CONTROL INVENTOR ZflfiW/GAver/( v Ear/mum Ema/NE ATTORN EY Patented Feb. 22, 1938 UNITED STATESPATENT OFFICE,

POWER PLANT Ludwig Lustlg, Manhasset, N. Y. Application June 25, 1934,Serial No. 732,196

8 Claims.

My invention relates to power plants and particularly to power plantsincluding an internal combustion engine and a super-charger forsupplying air or an explosive mixture to the engine.

In using a super-charger with an internal combustion engine the air orthe explosive charge is admitted to the engine cylinder under pressure.Therefore, after explosion of the charge the quantity, the volume andthe temperature of the exhaust gases leaving the cylinder areconsiderably greater than when the super-charger is not employed. Thisincrease in volume of the exhaust gases gives rise to considerable backpressure which tends to offset the advantages gained by the use of thesuper-charger. For example the resistance to the passage of the largevolume of exhaust gases from the cylinder presented by the valves,exhaust. manifold, etc., causes a substantial portion of the exhaustgases to remain in the cylinder when a new charge is admitted. Inordinary operation with a supercharger the back pressure of these gasesmay amount to as much as 20 or 30 lbs. per square inch above atmosphericpressure. For this reason considerable difficulty is experienced inproperly scavenging the cylinder preparatory to the introduction of thesucceeding explosive charge. The explosive charge which is subsequentlyintroduced into the cylinder is, therefore, diluted' by the remainingexhaust gases and the amount of the air or explosive mixture actuallyadmitted to the cylinder is reduced. The force required to operate thevalves and to expel the exhaust gases from the cylinder is alsoincreased when a super-charger is employed due to the increased pressureof the gases in the cylinder at the completion of the piston stroke.Furthermore, the temperature of the exhaust gases leaving the engine ishigher when a super-charger is employed and thus the heat contained inthe gases is wasted.

In accordance with my invention the back pressure of exhaust gasesleaving the engine cylinder 7 is reduced and in fact a suction or subatmospheric pressure may be produced so as to aid in the removal of theexhaust gases from the cylinder. scavenging of the cylinder is thereforeimproved, the amount of air or explosive mixture introduced into thecylinder is increased and the force required to operate the valves andto expel exhaust gases from the cylinder is reduced.

The means employed for reducing the back pressure on the cylinder inaccordance with my invention utilizes the heat contained in the exhaustgases as a source of energy for operating the same. Furthermore, thisenergy may also be used for operating the super-charger thus increasingthe efliciency of the power plant.

In that form of my invention hereinafter de- 5 scribed, heat containedin the exhaust gases is employed in the generation of steam for theoperation of the exhauster for reducing back pressure of the exhaustgases and for operating the super-charger through the use of a turbine.

One of the objects of my invention is to provide a power plant includingan internal com-' bustion engine and a super-charger together with anexhauster wherein back pressure of the ex-v haust gases is reduced. 18

Another object of my invention is to provide mechanical means forreducing back pressure on the engine.

A further object of my invention is to utilize waste heat from. theengine for reducing the back pressure of the exhaust gases.

Another object of my invention is to render the admission of air or anexplosive mixture to the engine cylinders and the scavenging of thecylinders independent.

Another object of my invention is to provide a waste heat boilerutilizing heat in exhaust gases leaving the engine to generate steam forsupplying power to actuate a super-charger for the engine and anexhauster functioning to reduce .back pressure of the exhaust gases.

A further object of my inventionis to provide means for simultaneouslyeffecting thermal and mechanical evacuation of exhaust gases from asuper-charged internal combustion engine.

These and other objects of my invention will appear from the followingdescription thereof in which reference is made to the accompanyingfigures of the drawings illustrating typical embodiments thereof.

In the drawings:

Fig. 1 is a vertical sectional view of one form of power plant embodyingmy invention;

Fig. 2 is a vertical sectional view of a portion of the mechanism shownin Fig. 3 taken. on the 45 line 2-2 of Fig. 3; V

Fig. 3 illustrates an alternative construction of certain elements ofthe combination;

Fig. 4 is a sectional view of a detail of the device shown in Fig. 3taken on the line 4- 4; and 50 Fig. 5 illustrates a further alternativeconstruction adapted for use with the device as shown in Fig. 1. 4

In that form of my invention chosen for illustration in Fig. 1, thedevice comprises an internal combustion engine 2 having a cylinder andan intake manifold 6 through which air or an explosive charge is passedto the various cylinders of the engine from the conduit 8. An exhaustmanifold ill connected to the cylinders 4 through which exhaust gasesare passed communicates with the exhaust conduit l2.

In order to supply the engine with air or an explosive mixture underpressure a super-charger N is employed. As shown, the super-chargercomprises an impeller l6 mounted on a shaft I8 which is rotatable athigh speed to draw air in through the opening 20 and to discharge thesame to the engine cylinders under the desired pressure through conduit8. The construction and operation of super-chargers of this, type iswell known and may be varied to meet the needs of any particularinstallation.

While the super-charger may be driven from the engine or any othersuitable source of power, I prefer to relieve the engine of this burdenin order to increase the poweravailable for useful work. For this reasonI utilize heat in the exhaust gases as a source of energy for theoperation of the super-charger. This is eflected 'by passing the hotexhaust gases from the engine cylinders to a waste heat boiler 22through the exhaust conduit H. The boiler, which may be of any suitableconstruction, is shown to comprise a lower chamber II to which theexhaust gases are admitted and with heating tubes 26 through which thehot exhaust gases pass in heat exchanging relation with water in thecasing 28. The upper ends of the tubes communicatewithanupperchamberlllfromwhich thegases are withdrawn by an cxhauster ashereinafter described.

In order to pre-heat water supplied to the waste heat boiler forproducing steam, I prefer to provide suitable circulating means forheated water from the en ine cooling system to the casing 2. as neededto maintain the. desired amount of waterintheboilen, For this purposethecooling system includes es II extending aboutthecylinderwallstowhichcoolwaterisadmitted through an inlet 32 and fromwhich heated water is withdrawn through an outlet 8|. Watercirculatedinthiswayispreheatedsothat heatcon- .tainedintheexhaustgasespassingtothe waste heat boiler is used primarily-in thegeneration of steam and only a relatively small amount of such heat isrequired for raising the temperature of the boiler water. Ordinarily theboiler is not capable of convertingall of the cooling water circulatings5 cooling system into steam and I therefore provide the outlet 34 witha by-pass 36 for returning a portion of the cooling wa'terto the coolingsystem. Theremaining water is used as feed-water for the boiler and isintrooo duced into the same by means of a pump II or other means, drivenby a suitable controllable prime mover. The additional cold waternecessary to maintain the supply of cooling water passing to the engineis supplied through a conas duit 40 provided with suitable valves ll.

Steam produced by the absorption of heat fromtheexhaustgasesthroughthewasteheat boiler is utilized in the form of myinvention illustrated for driving a turbine 42. Any suitable typeofturbinemaybeemployedforthis p such as the single stage turbineillustrated. Tim comprises a rotorv 44' having blades 46 against whichsteam is projected through the nozzles 48. Thesteamfromtbecasing 2|ottheboiler through the passage II to the annular chamber 52 which isprovided with any desired number of nozzles 48 located at suitablepositions adjacent the blades of the turbine.

The pressure of the steam generated in the waste heat boiler will dependlargely upon the 5 type of boiler employed, the construction andoperation of the turbine and engine and various other factors. However,in order to increase the efliciency of the turbine and to obtain themaximum pressure differential on the opposite sides 10 thereof, I preferto provide communication between the annular'exhaust chamber 54 of theturbine and suitable pressure reducing means such as anexhauster-condenser 56. Suflicient cool water is introduced into theexhauster to 15 effectively condense the steam from the turbine so thatthe exhauster functions also as a condenser producing a maximum pressurediiferential on the opposite sides of the turbine and increasing theamount of power derived therefrom. go

In order to reduce back pressure of exhaust gases passing from theengine cylinder the exhauster-condenser associated with the turbine isprovided with communication with the upper chamber 30 of the boilerthrough the passage 58. as

With this construction the exhaust gases after through the waste heatboiler wherein they are considerably reduced in temperature pass to theupper chamber 30 of the boiler and thence to the exhauster It throughthe e an I! to the annular chamber II and 62. As shown the exhaustercomprises a rotatable impeller 64 on shaft l8 by memo! which the exhaustgases are forcibly withdrawn from the waste heat boiler and from theengine cylinders. 36 The gases enter the exhauster tangentially and inthe direction of rotation thereof near the center and are cooled bywater introduced through inlets '6 supplied through pipes 61 shown inFig.

2. These inlets are positioned and directed so as 49 to bring the coldwater into intimate contact with the exhaust gases and with the steamentering the exhauster-condenser through the es II and a respectively.Furthermore the turbuperature and volume of the exhaust gases isdecreased as much as possible. This reduction in volume in the exhaustgases increases the 5; density thereof so that the exhauster operatesmore effectively to reduce the back pressure on the engine. Thecondensate and cooled exhaust gases pass from the exhauster through theoutlet II to a trap II, where liquids are separated from so the gases.

In the operation of the power plant shown in Pig. 1 and described abovethe super-charger supplies air or an explosive mixture to the engineunder pressure to the cylinder of the engine as where it is'utilized onexplosion for producing power. The resulting hot gases are withdrawn andforced from the engine cylinder upon completion of the expansion cycleby means of the exhauster I6 and the cooling and contraction of 70tbegasesin'their w w e throughthewaste heat boiler. The action of theexhauster in withdrawing the exhaust gases from the engine cylinderrenders it possible to delay the opening of the intake valve somewhatsince it is unn to 75 rely upon the admission of the succeeding air,orexplosive charge to assist in the scavenging of the cylinder. In otherwords the intake and exhaust cycles need not overlap as in presentoperation so that there need be no loss in the admission of unused airor explosive mixture to the cylinder.

with the arrangement described the exhauster and super-charger arecarried by the same shaft and driven directly from the turbine. Whilethis construction is not essential to my invention itinsures'corresponding and uniform operation of the exhauster and.super-charger. Thus any change in the pressure or volume of the airsupplied to the engine by the supercharger is met by a correspondingchange in the action of the exhauster. Furthermore, the supply of heatto the boiler from the exhaust gases is dependent in part at least onthe velocity of flow of the gases so that the supply of steam to theturbine is varied by the action of the other elements of thecombination.

Ordinarily it will be found on starting the engine that the temperatureof the boiler water is low and the water from the'engine cooling systemis comparatively cool. The piston and cylinder walls may also be cool orcold. For this reason the temperature of the exhaust gases passing tothe waste heat boiler is often much lower when the engine is startedthan will be the case after the engine has been operated for some time.On the other hand the demand for power from the engine is frequently ata maximum on starting so that it may be important at such times for thesuper-charger to be operated and for the back pressure of the exhaustgases to be reduced. However, although the demands for steam from thewaste heat boiler are high steam is not available for proper operationof the turblue to drive the supercharger and exhauster. In order toovercome this difllculty I have shown in Fig. 3 a construction fordriving the supercharger and exhauster independently of the turbineuntil such time as the pressure of steam in the boiler has become highenough to drive the turbine and operate the super-charger and ex--hauster satisfactorily. In this construction the shaft 14 of the turbine42' is provided with a clutch I6 of suitable construction normally urgedinto disengaged position by a spring 18 to permit the super-charger l4and exhauster 56' to be freely rotated while the turbine remainsstationary. The right hand member of the clutch in Fig. 3 is carried bya shaft 80 to which the rotor 64' of the exhauster is keyed. The rotorl6 of the super-charger may be secured in any suitable way to a hollowshaft 84 which preferably is formed integral with therotor for theexhauster. The means shown comprises a nut 86 cooperating with ashoulder 81 on shaft 84. The outer extremity of the tubular shaft 84 isprovided with a separable coupling 88 which is connected with the shaftof an electric motor 90 for driving the supercharger and exhausterindependently of the turbine when the engine is being started. Thecoupling means employed is preferably in the form of a friction clutchadapted to provide a driving connection with the motor.

able -longitudinally thereof by means of a pivoted lever 94 having ayoke 95 engaging the collar 92. Movement of the lever 94 to the leftserves to disconnect clutch 88 from the motor 99 and to move clutchmember 19 into engagement to connect the turbine to shaft 88 for drivingthe impellers of the super-charger and exhauster. The selection of thesource of power employed is preferably effected automatically inresponse to a condition of an elementof the power plant. As shown lever94 is actuated by means of a pressure operated device, such as thesylphon bellows 98 communicating with the upper portion of the wasteheat boiler. In order to .prevent free escape of steam from the boilerduring the starting period and to build up suflicient steam pressure inthe boiler to supply the necessa power to the turbine, the bellows 96may also serve to actuate valve 91 to admit steam to the turbine whenlever. 94 is moved to disengage the clutch for the motor 90 and connectThrottle 99 may operation of the completing and breaking the electriccircuit for energizing the motor 99 so as to maintain the motor inoperation until the pressure within the waste heat boiler has reached apredetermined point, say lbs. per square inch. Thereafter upon theoperation of the sylphon bellows, or pressure responsive means, thelever 94 is actuated'and the motor energizing circuit is broken so thatthe turbine is substituted for the motor as a source of power fordriving the supercharger and exhauster and the motor is allowed toremain idle.

In the operation of the mechanism shown in Fig.- 3 the lever 94 onstarting'the engine is in position to complete the motor circuit byengagement of the segment 98 with the contacts I90. In this position theclutch operating shaft 80 is withdrawn to the right holding clutch 88 inconnected position for driving the super-charger and exhauster from themotor. The clutch member I9 is then held out of engagement with thecoopcrating element carried by shaft 14 of the turbine so that theturbine may remain idle. The engine is thus operated supplying air or anexplosive mixture to the engine under pressure and relieving backpressure of the exhaust gases by the action of the exhauster. Heatcontained in the exhaust gases is taken up by water in the waste heatboiler 22' raising the temperature thereof and converting it into steam.When the pressure of the steam has reached a suitable point the pressureresponsive means or sylphon bellows is actuated to open valve 91 toadmit steam to the turbine and to force the lower end of the lever 94 otwardly to move the collar 92 and clutch operating shaft 89'to the leftdisengaging the motor clutch 88 and bringing the clutch element 16 intoengagement connecting the turbine to the rotors of the super-charger andexhauster for driving the same. At the same time the circuit forenergizing the motor is broken by movement of the segment 98 on thelever 94 out of engagement with the contacts I88 which form a part ofthe motor circuit. Thus the motor remains idle when the turbine drivesthe super-charger and exhauster whereas the turbine is disconnected whenthe motor is used for driving the supercharger and exhauster. Thetransfer from one source of power to the other for driving theseelements is effected by the pressure actuated means to insure properoperation 01' the supercharger and exhauster at all times.

In Fig. 5 oi. the drawings I have illustrated alternative means forinsuring proper operation of the super-charger andexhauster during theinitial operation of the power plant. In this construction the wasteheat boiler is provided with a supplemental source 01' heat such as theoil or gas burner I02 projecting into the chamber 24 in the base oi thewaste heat boiler. The burner is designed to be operated to maintain thetemperature of the boiler water sufllciently high to permit theimmediate production of steam when the engine is started or to provide asurplus of steam during the initial period of operation if this shouldbe desirable. The supplemental heating device may be operated by a motorI under the control of a thermostatic device I 06 responsive to changesin temperature of the exhaust gases in the exhaust conduit II. For thispurpose the thermo-couple I0. is provided which as shown is located inthe exhaust conduit, the mechanism used being oi any suitable type suchas that disclosed in the patent to Mertelmeyer and Koester 1,203,230. I

With this construction the supplemental heating device is operatedpreparatory to starting the engine so as to raise the temperature of theboiler water and generate sui'ilcient steam to operate the turbine. Whenthe engine is started the exhaust gases are drawn through the waste heatboiler by the exhauster adding their heat to that oi. the supplementalheating device and acting upon the thermo-couple to reduce the supply oiheat from the burner I02 proportionately. As the temperature of theexhaust gases rises upon the continued operation 0! the power plant therequirement for heat from the burner III! is decreased and the amount ofheat provided is correspondingly reduced by the action 01' thethermostatic device I until the additional heat supply is reduced to aminimum or eliminated altogether.

This construction insures a continuous supply of steam for the turbineat all times when required and renders it possible to regulate the steamproduction to accommodate varying loads upon the power plant.

In each of the forms of my invention illmtrated in Figs. 1 and 3, theturbine, exhauster and super-charger are constructed as separate.

castings mounted upon the top 01' the waste heat boiler so'as to presenta compactinexpensive construction adapted to be readily applied toexisting power plants without material alteration.

While I'have illustrated and described certain forms 01' my invention itwill be apparent that my invention is not limited to the constructionsshown. 'lhe power plant may include two cycle or tour cycle internalcombustion engines oi either the Diesel or Otto type. The particularform or waste heat boiler employed as well as the former turbine,exhauster, and super-charger may be varied considerably with eachinstallation depending upon the size, cost and other factors as desired.It should, therefore, be understood that the form of power plant hereinillustrated and described is intended to represent a typical embodimentof my invention and is not intended to limit the scope thereof.

What is claimed is:

i. A power plant having in combination, an internal combustion engine, asuper-charger for said engine, a waste heat boiler utilizing heat inexhaust gases from said engine to produce steam, a turbine for drivingsaid super-charger and driven by steam from said waste heat boiler,

in said boiler for actuating said alternative device.

2. A power plant having in combination, an internal combustion engine, asuper-charger for said engine, a waste heat boiler utilizing heat inexhaust gases from said engine to generate steam, a turbine utilizingsteam from said waste heat boiler, a rotary exhauster-condenser servingto reduce back pressure of exhaust gases from said engine and tocondense steam from said turbine, means for supplying cooling liquid tosaid exhauster-condenser, a shaft rotated by said turbine and impellersfor said super-charger and said exhauster driven by said shaft.

3. A power plant having in combination, an internal combustion engine, asuper-charger for said engine, a waste heat boiler utilizing heat inexhaust gases from said engine to generate steam, a turbine for drivingsaid super-charger and driven by steam from said waste heat boiler, anexhauster condenser driven by said turbine serving to reduce backpressure of exhaust gases of said engine and to condense steam from saidturbine to increase the difierence in pressure on the opposite sides ofsaid turbine, and alternative means for supplying power to drive saidsuper-charger and said exhauster-condenser, and means responsive to thepressure of the steam in said boiler for actuating said alternativemeans.

,4. A power plant comprising an internal combustion engine, asuper-charger for said engine, a waste heat boiler utilizing heat inexhaust gases from said engine, an exhauster for drawing ex- .haustgases through said waste heat boiler, a

internal combustion engine, a super-charger for said engine, a wasteheat boiler utilizing heat in the exhaust gases to generate steam, aturbine driven by steam from said boiler, an exhauster communicatingwith said turbine and said waste heat boiler, means for introducing acooling medium into said exhauster to condense steam from the turbineand to cool said exhaust gases, a motor for driving said super-chargerand exhauster, and means responsive to variations in the pressure 01'steam in said boiler to connect either said turbine or said motorselectively to the super-charger and exhauster to operate the same.

I 6. A power plant having in combination an internal combustion engine,a super-charger for said engine, a waste heat boiler utilizing heat inthe exhaust gases'to generate steam, a turbine driven by steam from saidboiler, common means for reducing back pressure on said engine and onsaid turbine, a motor for actuating said means and super-charger andmeans responsive to variations in the pressure of steam in said boilerto connect either said turbine or said motor selectively to thesupercharger and said means to operate the same. 1

7. A power plant having in combination an internal combustion engine, asuper-charger for said engine, a waste heat boiler utilizing heat in theexhaust gases to generate steam, a turbine driven by steam from saidboiler, an exhauster communicating with said turbine and said waste heatboiler, a motor for driving said super-charger and exhauster and meansresponsive to variations in the pressureot steam in said boiler toconnect either said turbine or said motor selectively to thesuper-charger and exhauster to operate the same.

8. A power plant comprising an internal combustion engine within which apiston reciprocates, a super-charger for supplying air underpressure tosaid engine, a waste heat boiler utilizing the heat from the exhaustgases from'sald engine to produce steam, a turbine for driving saidsuper-charger and driven 'by steam from said waste heat boiler, commonmeans for reducing pressure on the exhaust side of said turbine and forreducing the back pressure of said exhaust' gases irom said internalcombustion engine, an alternative device driven independently of saidengine for actuating said supercharger and said common means, and meansresponsive to the pressure of the steam in said boiler for actuatingsaid alternative device.

" LUDWIG LUS'I'IG.

